I'd always assume that notes are being taken, even if they're not being taken in session with a client. It's for legal reasons (like if there is a subpoena, or in instances where there is suspected child abuse, or harm to self and/or others... having a record is very important), and how in the world would I expect a T to remember all the details of my life if they didn't actually take some notes, even after a session?

(I should also say I'm biased in that I'm taking a class as part of my diploma and we've got an entire course on record keeping and confidentiality, so I'm seeing it from both perspectives, as a client of a therapist and as a person who will eventually be working in the helping profession).